Question details

Is it posible to configure Modbus TCP Slave for redundant AC902F?

Last time I asked a question about communication between AC902FR and PP877K, I was told that I should use Modbus TCP. And our designated ABB service engineer said the same, after a lot of BOM revision. But I just found out that it seems like Modbus TCP doesn't support redundancy toggle of redundant process station. In FreeLance Manual it says: "For process station in a redundant configuration an interruption of Modbus communication will not result in a redundancy toggle. Only a system alarm will be trip if the Ethernet interface is affected by the interrupted communication.". Does that mean no? Is there any other way configure redundancy for this communications?

Answers

0

Hello TruongND,

The manual says that Modbus TCP failure does not trigger the redundancy toggle, not that You can't use it with redundant controllers. You can do it automatically in Your program (with Force Redundancy Toggle function block), but remember to write it so You won't casue a redundancy toggle loop in which the controller toggles back and forth as a result of Modbus master failure.

Thank you for quick answer. And what about configure redundancy controller in Panel Builder 800 Ver. 6? I find a tab call "Stations" in Modbus Master Settings windows in Tags Function, but I don't know how to configure it.